Clock



FIG. 1 is a front elevational view of a clock showing my new design,

FIG. 2 is a top plan view thereof, the bottom being plain and unornamental;

FIG. 3 is a bottom plan view thereof,

FIG. 4 is a rear elevational view thereof, and

FIG. 5 is a right side elevational view thereof, the left side being a mirror image. 

The ornamental design for a clock, as shown and described. 